The aim or objective of the project is to determine interference among two adjacent tall buildings. Computational fluid dynamics was used after modelling the structures in stiff full-scale forms. Using the interference effects from another square plan tall buildings of the same height at 0° WIA, ANSYS CFX analyses pressure variations on sidewalls of a square plan tall building. It can be said that these buildings are closely located – from 0.4h to h, h being a height of a building. Using the square plan shaped building in its isolated condition as a point of comparison, the analysis also compares it to square shape buildings located in other places. Comparisons are illustrated using the interference factors (IF) and IF contours. At times there is recorded a deviant pressure distribution. Apart from that, it is noticed that the interfering buildings have a shielding and channelling influence over the square plan formed building. When there is interference on square plan-shaped building faces, the pressure distribution becomes unpredictable. We get the Cp for each face of the square plan-shaped building in each interfering situation by simply multiplying IF and Cp separately with the integral factor of two situations in an isolated case.